IMO C

from 2: by knowing a numerator we can never say whether it will be terminating or nor
from 1: r/(225^2) = r/(15^4)
when r = 15^4 then it will be terminating
when r = (15^3)*5 then it will be non terminating.

Now combine 1 and 2 as 81 = 3^4
r/s = (3/15)^4 = (0.2)^4 is terminating.

Yep, that's correct

Just wanted to share this with other users so that they don't make the same dumb mistake as me and chose (A)

Hey kmittal82:

Great question - and I'd also add this bit of GMAT strategy to it, too: use statement 2 to help you double-check statement 1.

Because the distinction between A and C comes down to "do you need statement 2 or not", statement 2 may well provide essential information. Therefore, if 1 seems sufficient on its own and 2 definitely doesn't, ask yourself why 2 is there.

Here, I thought a lot like you at first glance - 225 is a multiple of 9, so it looked like you were going to get something repeating like .1111111 out of it. But immediately when I saw statement 2 I though "that's a multiple of 9...twice", and that's what clicked my thinking back to the thought that:

1/9 = .1111111
2/9 = .2222222
etc.
8/9 = .8888888
but 9/9 = 1, because the 9s cancel each other out and you're left without a repeating decimal.

So then I recognized that as long as I can account for every 9 in the denominator with one in the numerator, the decimal will be determined by the other factors in the fraction.


Essentially, a closer look at 2 saved me from a way-too-quick assumptive answer on 1, and that happens enough that it's worth being aware of. My rule of thumb - if 1 seems sufficient and 2 seems pretty far from it, there's a great chance that 2 is there to clarify something that 1 doesn't on its own, so I should go back and reconsider 1, and reconsider it by thinking about what 1 has taught me.

mittal sahab.. vry good qn. Thanks for sharing.